Arch Dis Child 2002;86:282-285
Background: rocalcitonin (PCT), a precursor of calcitanin, is a recognised marker of bacterial sepsis, and high concentrations correlate with the severity of sepsis. PCT has been proposed as an earlier and better diagnostic marker than C reactive protein (CRP) and white cell count (WCC). This comparison has never been reported in the differentiation of meningococcal disease (MCD) in children presenting with a fever and rash.
Aim: To determine if PCT might be a useful marker of MCD in children presenting with fever and rash.
Methods: PCT, CRP, and WCC were measured on admission in 108 children. Patients were classified into two groups: group I, children with a microbiologically confirmed clinical diagnosis of MCD (n = 64); group II, children with a self limiting illness (n = 44). Median ages were 3.57 (0.07-15.9) versus 1.75 (0.19-14.22) years respectively. Severity of disease in patients with MCD was assessed using the Glasgow Meningococcal Septicaemia Prognostic Score (GMSPS).
Results: PCT and CRP values were significantly higher in group I than in group II (median 38.85 v 0.27 ng/ml and 68.35 v 9.25 mg/l; p < 0.0005), but there was no difference in WCC between groups. Sensitivity, specificity, and positive and negative predictive values were higher for PCT than CRP and WCC. In group I, procalcitonin was significantly higher in those with severe disease (GMSPS [greater than or equal to] 8).
Conclusions: PCT is a more sensitive and specific predictor of MCD than CRP and WCC in children presenting with fever and a rash.
Despite introduction of the new meningococcal C conjugate vaccine, meningococcal disease (MCD) remains an important cause of morbidity and mortality in childhood. There is now good evidence that mortality from this disease is falling, (1) but a high index of suspicion, prompt diagnosis, and aggressive management are essential if mortality and morbidity are to be reduced further.
The ill child who presents with fever and a rash will almost always be managed as MCD with intravenous antibiotics, aggressive fluid resuscitation, inotrope support, and ventilation if necessary. In contrast, the relatively well child with fever and a rash may present a diagnostic dilemma for the clinician. Most clinicians would err on the side of caution and admit such children. They might also be started on intravenous antibiotics pending the results of blood culture and polymerase chain reaction assay to detect meningococcal DNA. A significant proportion of such children may have a viral illness, (2 3) therefore managing them as cases of meningococcal septicaemia would be subjecting them to unnecessary antibiotics and hospital admission.
Procalcitonin (PCT) is a 116 amino acid protein with a molecular mass of 13 kDa, which is a precursor of calcitonin. In neuroendocrine cells (C cells of the thyroid, pulmonary, and pancreatic tissues), it undergoes successive cleavages to form three molecules: calcitonin (32 amino acids), katacalcin (21 amino acids), and an N-terminal fragment (57 amino acids). Raised concentrations of a substance immunologically identical to PCT in sepsis were first described by Assicot and colleagues, (4)...